P33 EFFECTIVENESS AND SAFETY OF BELANTAMAB MAFODOTIN IN PATIENTS WITH RELAPSED/REFRACTORY MULTIPLE MYELOMA IN REAL-LIFE SETTING: THE ALFA STUDY
Authors: M. Roussel, N. Texier, R. Germain, S. Sapra, P. Paka, N. Kerbouche, X. Colin, X. Leleu
Journal: HemaSphere (2023)

Objectives: Patients with relapsed/refractory multiple myeloma (RRMM) refractory to immunomodulators, proteasome inhibitors and anti-CD38 antibodies have few therapeutic alternatives. Belantamab mafodotin (belamaf)—an antibody-drug conjugate targeting B-cell maturation antigen—showed promising results in the DREAMM-2 trial. The ALFA study aims to describe real-world belamaf effectiveness and safety in patients with RRMM. Methods: ALFA is a non-interventional, retrospective study of patients with RRMM initiating belamaf in 45 centres in France during early access programmes from 27 April 2020 to 30 June 2021. Patient characteristics, overall response rate (ORR) (≥partial response [PR]), clinical benefit rate (CBR) (≥minimal response [MR]), ≥very good PR (VGPR) rate, progression-free survival (PFS), overall survival (OS) and safety were assessed. Subgroup analyses for PFS and OS were performed. Results: In total, 184 patients initiated belamaf (median follow-up, 7.8 months). Median time from diagnosis to belamaf initiation was 6 years; 107 patients (58.2%) had ≥5 prior therapy lines. At initiation, 53.3% were male; median age was 70 years (29.9% aged ≥75 years); 47.7% had renal failure; 78.8% were penta-exposed; and 8.3% had extramedullary disease. Among patients with available data (n=156), 36.5% had an Eastern Cooperative Oncology Group Performance Status ≥2. Cytogenetic profiles at diagnosis were available for 83 patients (45.1%), 27 (32.5%) of whom had high cytogenetic risk defined as either t(4;14) or del(17p) or t(14;16); 47.7% had ophthalmological history (cataract, 52.7%). Belamaf was delivered by intravenous infusion in 21-day cycles. Median dose at initiation was 2.5 mg/kg (range, 1.6–3.0). Median number of belamaf cycles was 3 (Q1–Q3, 2–7). The ORR was 32.7% (≥VGPR, 20.4%; PR, 12.3%) and 59 patients (36.4%) achieved clinical benefit; 26.5% had stable disease (SD) and 37.0% had progressive disease (PD). Overall, median PFS (mPFS) was 2.4 months (95 CI%, 1.9–3.2) and median OS (mOS) was 8.8 months (95 CI%, 6.3–11.6). No differences were found in subgroups according to cytogenetic risk, renal failure, age at belamaf initiation, penta-exposure and number of prior therapy lines. According to best response, mPFS was 20.6 months (95 CI%, 12.1 to not reached [NR]) in patients with ≥VGPR, 7.1 months (95 CI%, 4.6–9.4) in patients with PR and 1.6 months (95 CI%, 1.4–2.0) in the other patients (P<0.01). mOS was not reached in patients with ≥VGPR (1-year survival rate, 96.8% [95 CI%, 79.2–99.5]), 17.5 months (95 CI%, 7.7 to NR) in patients with PR and 5.6 months (95 CI%, 3.9–7.7) in the other patients (including MR, SD and PD) (P<0.01). In patients with a clinical benefit, mPFS was 9.7 months (95 CI%, 7.5–14.9) and mOS was not reached. Adverse events (AEs) were reported in 159 patients (86.4%); the most frequent were ocular AEs (n=103 [56.0%]). Keratitis/keratopathy and thrombocytopenia occurred in 41.8% and 13.6% of patients, respectively. Incidence of infusion reaction was 3.3%. Ocular AEs led to dose modification, temporary interruption and permanent discontinuation in 19.6%, 11.4% and 12.5% of patients, respectively. Conclusions: These data, presented from the largest real-life study conducted to our knowledge, confirm previous results from DREAMM-2.